#include "stdafx.h"

/*  -- translated by f2c (version 19940927).
   You must link the resulting object file with the libraries:
	-lf2c -lm   (in that order)
*/

#include "hnum_f2c.h"
namespace harlinn
{
    namespace numerics
    {
        namespace SuperLU
        {
            /* Subroutine */ 
            int ssyr2_(char *uplo, integer *n, real *alpha, real *x, integer *incx, real *y, integer *incy, real *a, integer *lda)
            {


                /* System generated locals */
                integer a_dim1, a_offset, i__1, i__2;

                /* Local variables */
                static integer info;
                static real temp1, temp2;
                static integer i, j;
                    
                static integer ix, iy, jx, jy, kx, ky;
                    


            /*  Purpose   
                =======   

                SSYR2  performs the symmetric rank 2 operation   

                    A := alpha*x*y' + alpha*y*x' + A,   

                where alpha is a scalar, x and y are n element vectors and A is an n 
  
                by n symmetric matrix.   

                Parameters   
                ==========   

                UPLO   - CHARACTER*1.   
                            On entry, UPLO specifies whether the upper or lower   
                            triangular part of the array A is to be referenced as   
                            follows:   

                            UPLO = 'U' or 'u'   Only the upper triangular part of A   
                                                is to be referenced.   

                            UPLO = 'L' or 'l'   Only the lower triangular part of A   
                                                is to be referenced.   

                            Unchanged on exit.   

                N      - INTEGER.   
                            On entry, N specifies the order of the matrix A.   
                            N must be at least zero.   
                            Unchanged on exit.   

                ALPHA  - REAL            .   
                            On entry, ALPHA specifies the scalar alpha.   
                            Unchanged on exit.   

                X      - REAL             array of dimension at least   
                            ( 1 + ( n - 1 )*abs( INCX ) ).   
                            Before entry, the incremented array X must contain the n   
                            element vector x.   
                            Unchanged on exit.   

                INCX   - INTEGER.   
                            On entry, INCX specifies the increment for the elements of   
                            X. INCX must not be zero.   
                            Unchanged on exit.   

                Y      - REAL             array of dimension at least   
                            ( 1 + ( n - 1 )*abs( INCY ) ).   
                            Before entry, the incremented array Y must contain the n   
                            element vector y.   
                            Unchanged on exit.   

                INCY   - INTEGER.   
                            On entry, INCY specifies the increment for the elements of   
                            Y. INCY must not be zero.   
                            Unchanged on exit.   

                A      - REAL             array of DIMENSION ( LDA, n ).   
                            Before entry with  UPLO = 'U' or 'u', the leading n by n   
                            upper triangular part of the array A must contain the upper 
  
                            triangular part of the symmetric matrix and the strictly   
                            lower triangular part of A is not referenced. On exit, the   
                            upper triangular part of the array A is overwritten by the   
                            upper triangular part of the updated matrix.   
                            Before entry with UPLO = 'L' or 'l', the leading n by n   
                            lower triangular part of the array A must contain the lower 
  
                            triangular part of the symmetric matrix and the strictly   
                            upper triangular part of A is not referenced. On exit, the   
                            lower triangular part of the array A is overwritten by the   
                            lower triangular part of the updated matrix.   

                LDA    - INTEGER.   
                            On entry, LDA specifies the first dimension of A as declared 
  
                            in the calling (sub) program. LDA must be at least   
                            max( 1, n ).   
                            Unchanged on exit.   


                Level 2 Blas routine.   

                -- Written on 22-October-1986.   
                    Jack Dongarra, Argonne National Lab.   
                    Jeremy Du Croz, Nag Central Office.   
                    Sven Hammarling, Nag Central Office.   
                    Richard Hanson, Sandia National Labs.   



                    Test the input parameters.   

    
                Parameter adjustments   
                    Function Body */
            #define X(I) x[(I)-1]
            #define Y(I) y[(I)-1]

            #define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)]

                info = 0;
                if (! lsame_(uplo, "U") && ! lsame_(uplo, "L")) {
	            info = 1;
                } else if (*n < 0) {
	            info = 2;
                } else if (*incx == 0) {
	            info = 5;
                } else if (*incy == 0) {
	            info = 7;
                } else if (*lda < max(1,*n)) {
	            info = 9;
                }
                if (info != 0) {
	            xerbla_("SSYR2 ", &info);
	            return 0;
                }

            /*     Quick return if possible. */

                if (*n == 0 || *alpha == 0.f) {
	            return 0;
                }

            /*     Set up the start points in X and Y if the increments are not both 
  
                    unity. */

                if (*incx != 1 || *incy != 1) {
	            if (*incx > 0) {
	                kx = 1;
	            } else {
	                kx = 1 - (*n - 1) * *incx;
	            }
	            if (*incy > 0) {
	                ky = 1;
	            } else {
	                ky = 1 - (*n - 1) * *incy;
	            }
	            jx = kx;
	            jy = ky;
                }

            /*     Start the operations. In this version the elements of A are   
                    accessed sequentially with one pass through the triangular part   
                    of A. */

                if (lsame_(uplo, "U")) {

            /*        Form  A  when A is stored in the upper triangle. */

	            if (*incx == 1 && *incy == 1) {
	                i__1 = *n;
	                for (j = 1; j <= *n; ++j) {
		            if (X(j) != 0.f || Y(j) != 0.f) {
		                temp1 = *alpha * Y(j);
		                temp2 = *alpha * X(j);
		                i__2 = j;
		                for (i = 1; i <= j; ++i) {
			            A(i,j) = A(i,j) + X(i) * temp1 
				            + Y(i) * temp2;
            /* L10: */
		                }
		            }
            /* L20: */
	                }
	            } else {
	                i__1 = *n;
	                for (j = 1; j <= *n; ++j) {
		            if (X(jx) != 0.f || Y(jy) != 0.f) {
		                temp1 = *alpha * Y(jy);
		                temp2 = *alpha * X(jx);
		                ix = kx;
		                iy = ky;
		                i__2 = j;
		                for (i = 1; i <= j; ++i) {
			            A(i,j) = A(i,j) + X(ix) * temp1 
				            + Y(iy) * temp2;
			            ix += *incx;
			            iy += *incy;
            /* L30: */
		                }
		            }
		            jx += *incx;
		            jy += *incy;
            /* L40: */
	                }
	            }
                } else {

            /*        Form  A  when A is stored in the lower triangle. */

	            if (*incx == 1 && *incy == 1) {
	                i__1 = *n;
	                for (j = 1; j <= *n; ++j) {
		            if (X(j) != 0.f || Y(j) != 0.f) {
		                temp1 = *alpha * Y(j);
		                temp2 = *alpha * X(j);
		                i__2 = *n;
		                for (i = j; i <= *n; ++i) {
			            A(i,j) = A(i,j) + X(i) * temp1 
				            + Y(i) * temp2;
            /* L50: */
		                }
		            }
            /* L60: */
	                }
	            } else {
	                i__1 = *n;
	                for (j = 1; j <= *n; ++j) {
		            if (X(jx) != 0.f || Y(jy) != 0.f) {
		                temp1 = *alpha * Y(jy);
		                temp2 = *alpha * X(jx);
		                ix = jx;
		                iy = jy;
		                i__2 = *n;
		                for (i = j; i <= *n; ++i) {
			            A(i,j) = A(i,j) + X(ix) * temp1 
				            + Y(iy) * temp2;
			            ix += *incx;
			            iy += *incy;
            /* L70: */
		                }
		            }
		            jx += *incx;
		            jy += *incy;
            /* L80: */
	                }
	            }
                }

                return 0;

            /*     End of SSYR2 . */

            } /* ssyr2_ */

        };
    };
};